SVG Blob Shape Builder🔒 100% local

Generate organic blob shapes as SVG paths. Perfect for backgrounds, illustrations, and design elements.

Complexity (Points)

Growth Factor

Base Radius

Seed

SVG Blob Shape Builder: related tools

SVG Cleaner SVG Pattern Builder Favicon Generator

Generates an organic blob as an SVG file from four controls: how many points the outline has, a growth factor for how far each point may bulge, the base radius and a seed. Point distances come from a small linear-congruential generator started at the seed, and the points are joined into a closed path inside a fixed two-colour SVG wrapper.

SVG Blob Shape Builder: how to use it

Set Complexity between 3 and 20 to choose how many points the outline has.
Set Growth Factor between 0.5 and 3; higher values make the radii vary more and the outline spikier.
Type a seed or press Randomize Seed, then press Generate Blob.
The shape is previewed in a square, with the SVG source underneath for copying.

SVG Blob Shape Builder: worked example

seed 1, complexity 5, growth 1.5, radius 100becomes

<svg viewBox="-120 -120 240 240" xmlns="http://www.w3.org/2000/svg">
  <path d="M 100 0 L 17.4 53.5 L -56.7 41.2 L -48.6 -35.3 L 29.8 -91.9 L 83.5 -0.0 Z" fill="#0A0F2C" stroke="#CC2B22" stroke-width="2" fill-rule="evenodd"/>
</svg>

The same numeric seed with the same sliders always produces this exact path. The fill and stroke colours are fixed by the generator.

SVG Blob Shape Builder: when to use it

Making a background shape for a hero section without opening a vector editor.
Producing variants of one blob by changing only the seed.
Getting a single self-contained SVG element you can paste into markup or into a CSS background.

SVG Blob Shape Builder: what it does not do

Only the numeric part of the seed is used. A label such as logo-v2 fails the numeric parse and falls back to the current timestamp, so it will not reproduce a shape.
Points are joined with straight line segments, so the outline is a polygon - at low complexity the flat edges are visible. There is no curve smoothing.
Fill, stroke and stroke width are hard-coded in the output; you have to edit them after copying.
The seed box starts as the page-load timestamp, so pressing Generate Blob twice without touching it gives two different shapes.

🫧SVG Blob Shape Builder🔒 100% local